Abstract

Preliminary results on a double-pole double-throw optical switch which utilizes two crossed channel waveguides in a LiNbO₃ substrate and a pair of parallel electrodes to induce total internal reflection (TIR) were reported by us at the 1980 Topical Meeting on Guided-Wave and Integrated Optics.⁽¹⁾ The straight channel waveguide intersection (termed 2Δn intersection) employed in this TIR switch differs from the conventional one. Contrary to the conventional intersection (termed Δn intersection), the refractive index change in the crossover region is twice that in the channel waveguides. As a result, the light wave is also guided in the crossover region and it is possible to achieve both low drive voltage and low crosstalk simultaneously by using a sufficiently small intersection angle. For example, a drive voltage of 5 volts for 93% switching efficiency and a crosstalk of -15.7 db were demonstrated in a switch with an intersection angle of 1.0 degree.⁽¹⁾ A 3 × 3 matrix switch which consists of four of the basic switches just described was also tested with encouraging results.⁽¹⁾

© 1982 Optical Society of America